Ecosystem Health Status Research Articles

Ecosystem health status and trophic modeling of an anthropogenically impacted small tropical estuary along India's west coast.

The tropical estuaries are characterized with high biological production and also impacted by anthropogenic activities. Describing these estuaries in terms of ecological data and trophic dynamics to reveal the ecological impacts is gaining attention recently. In this study, the ecological structure is analyzed for a heavily impacted small macrotidal tropical estuary, Ulhas river estuary (URE), situated near Mumbai megacity in the western coast of India, to delineate the impact of anthropogenic stressors on the ecosystem functioning. The URE is being exploited for sand and fisheries resources, and also faces risks from anthropogenic activities. The ecological data of URE were compiled for 2017-18 together with the most relevant literature estimates to construct an ecosystem model. A trophic organization in 20 functional groups was identified for URE using Ecopath modeling approach. The functional groups identified in the food web ranged from detritus and primary producers (trophic level (TL) = 1) to large pelagics (TL = 4.14). Detritivory: herbivory ratio (1.35) indicated that the detritus chain is dominant over the primary producer's chain. The total system throughput (TST) was estimated as 16 736.2 t km-2year-1. The indices such as net system production (NSP = 1 398.781 t km-2 year-1), total primary production/total biomass (TPP/TB = 25.17), biomass/total system throughput (TB/TST = 0.01), recycling index (Finn's Cycling Index = 13.94%), system omnivory index (0.3), relative ascendency (25.6%), and system overhead (74.4%) classified URE as an immature system. The eco-exergy index (30748.54 gm detritus equivalent m-2) showed that the ecosystem is a moderately stable and relatively less organized network. The estuarine fish community index (EFCI) yielded a value of 38 indicating the poor health status of the fish community in URE. The study delivers a comprehensive understanding of the ecosystem setting in URE and characterizes the prevailing condition. The ecological indicators analyzed here point towards a medium to a high level of impact in URE due to anthropogenic activities.

A multimetric nekton index for monitoring, managing and communicating ecosystem health status in an urbanized Gulf of Mexico estuary

Biological assessments have been used for decades to determine ecological conditions in aquatic environments, yet they have not been extensively applied in estuaries that serve as transition zones between freshwater and marine environments. We present the development and validation of a nekton (fish and selected macroinvertebrate) index for annual monitoring of ecosystem health in Tampa Bay, Florida. We relied on long-term fisheries independent monitoring data of the early recruit and juvenile life history stages of nekton in Florida’s inshore waters. A set of metrics that included measures of abundance, species diversity, trophic structure, and taxa of commercial or recreational importance were explored, and a subset was selected via statistical models. Reference conditions specific to each season and management section of the bay were established from the long-term dataset. The final Tampa Bay Nekton Index included five metrics: the total number of taxa, the number of benthic taxa, the number of recreational/commercial fishery taxa, the number of feeding guilds, and the Shannon-Weiner diversity index. Nekton index scores were calculated for each sample and averaged by bay management section and year and then a “stoplight” color-coding system, based on quantiles, was used to group index scores for communication and management. In general, Tampa Bay’s nekton community appears to be resistant to large-scale changes in functional structure. The index was sensitive to a prolonged red tide event but eventually returned to preperturbation levels, indicating nekton community resilience. This index will be incorporated into monitoring and managing strategies of the local estuary program. Because this index was developed specifically for Tampa Bay and relies on bay-specific reference conditions, the index cannot be directly applied to other systems, but the methodology is transferrable so similar indices could be developed for other ecosystems with long-term monitoring data. Furthermore, using regional data, the index could be expanded/developed to assess health status among estuaries to inform decisions on prioritization of limited resources.

Aquatic Ecosystem Health Assessment of Poyang Lake through Extension Evaluation Method

Freshwater lakes encounter a series of problems, such as a decline in lake water quality, a sharp decrease in biodiversity, and ecological degradation. As such, lacustrine studies by highly skilled professionals and managers with water resources at home and abroad have focused on assessing the aquatic ecosystem health status of lakes. In this study, the health status of the aquatic ecosystem in the largest freshwater lake in China (Poyang Lake) was assessed, and its temporal and spatial characteristics were illustrated. The index contained three element layers, including hydrologic characteristics, trophic status, and aquatic organisms. The health status of the aquatic ecosystem was classified into three categories: ‘good’, ‘moderate’ (subhealthy), and ‘bad’. It was examined through extension evaluation method. Results showed ‘moderate’ health status, whereas remarkable seasonal and spatially variations. The annual changes in the health status were remarkably due to the influence of complex hydrological and hydrodynamic conditions. This study provides an overall understanding of the aquatic ecosystem evaluation in Poyang Lake. Such an understanding is vital for environmental conservation and identification of causes of the aquatic ecosystem degradation in Poyang Lake.

A first approach to build and test the Copepod Mean Size and Total Abundance (CMSTA) ecological indicator using in-situ size measurements from the Plankton Imager (PI)

Being located between primary producers and fish, zooplankton are a key element of marine food webs, the trophic structure of which is dependent upon the size distribution of species. Changes in zooplankton community size structure have the potential to alter the food web structure and ultimately the quality of food for planktivorous fish. Zooplankton therefore play a key role in overall ecosystem health and are ideal indicators of environmental variability due to their short life cycle and sensitivity to environmental changes. In this study, we used a first approach to build and test the Copepod Mean Size and Total Abundance (CMSTA) ecological indicator in the Celtic Sea, using a similar methodology to that of the HELCOM Mean Size and Total Stock (MSTS) indicator. We explored relationships between zooplankton mean size, total abundance and biomass with hydrographic and biological variables representative of both lower and higher trophic levels (i.e. Chlorophyll-a levels and the biomass distribution of herring, sardine, anchovy, sprat and horse mackerel). Herring, the species with the strongest preference for larger prey, was the only fish that displayed a statistically significant positive correlation with copepod mean size. Displaying the stations spatially within the 2-dimentional (copepod mean size versus abundance) indicator plots, resulted in a strong pattern of herring distribution related to areas where copepods were the largest rather than the most abundant. Our preliminary results are in line with those obtained from previous studies, confirming that zooplankton mean size is able to reflect the state of the food web, and thus reinforce the importance as zooplankton size as a key trait to be routinely monitored. Our in-situ zooplankton size measurements were collected with the Plankton Imager (PI). The ability of this automated system to take measurements for every single organism in a sample meant that the mean size was calculated based on the actual size distribution of the sampled population. Additionally, because of the non-normal distribution of copepod size, the geometric mean was found to be a much more representative description of the community size than the arithmetic mean. We have demonstrated (1) the potential of the CMSTA as a potential indicator of ecosystem health status and climate effects, and (2) the value of the PI in collecting routine in-situ zooplankton size information for improving the power of the mean size indicator approach to describe the community structure.

Elemental Composition and Health Risk Assessment of Giant Mudskipper (Periophthalmodon schlosseri) From the Intertidal Zone of the West Coast of Peninsular Malaysia

The elemental pollution in the intertidal zone of the West Coast of Peninsular Malaysia is of concern because this place is an ultimate sink of anthropogenic contaminants. In this study, the elemental concentrations (Al, Fe, Ba, Co, Cu, Cr, Mn, Ni, Pb, Zn, As, and Cd) in various tissues (muscle, gill, liver, gastrointestinal tract, and scale) of the giant mudskippers (Periophthalmodon schlosseri) from the West Coast of Peninsular Malaysia were determined by the inductively coupled plasma-mass spectrometry. The potential health risks associated with fish muscle consumption were assessed using estimated weekly intake (EWI), target hazard quotient (THQ), and target cancer risk (TR). The results showed that relatively high concentrations of Fe (1,641.91 ± 96.77 mg/kg), Ba (7.07 ± 0.05 mg/kg), Co (0.32 ± 0.00 mg/kg), Mn (36.08 ± 0.04 mg/kg), and Ni (4.43 ± 0.06 mg/kg) were found in the fish scales, suggesting the uptake waterborne elements via dermal exposure. However, all studied elements in the fish muscle were below the national and international food permissible limits. Health risk assessment through the estimation of THQ suggested that long-term exposure of As through fish consumption would cause possible non-carcinogenic risk. Also, the estimation of TR indicated that consumers are susceptible to cancer risks because of Cr and As exposure via fish consumption. Thus, for a developing country like Malaysia, it is recommended to include continuous monitoring of intertidal zones, using potential bioindicators, to assess ecosystem health status and safeguard human health. Additionally, mitigation strategies to address estuaries contamination and efforts to conserve and sustain natural resources should be established.

喀斯特地区不同石漠化程度草地根系分解与周转特征

为探明喀斯特地区不同草地根系动态及其对石漠化的响应，本文以3种不同石漠化程度（潜在、中度和强度）的草地为研究对象，采用连续根钻法和分解袋法，于2017年3月-2018年1月，分析了不同石漠化草地的根系垂直分布、季节动态、分解、周转及其与土壤因子的关系。结果表明，3种石漠化草地的根系生物量随着土层的深度增加呈逐渐降低的趋势，潜在和中度石漠化草地的根系生物量均呈现明显的单峰型季节变化，强度石漠化草地的根系生物量变化不显著。3种石漠化草地的根系分解速率受土壤有机碳、全钾、全氮、含水量、电导率、温度等的影响显著，随分解时间均表现为"快-慢-快"的变化趋势，根系的年分解率分别为64%、56%和58%。3种草地根系完全分解（分解率为95%）时，分别需要1174天、1351天和1878天。随石漠化程度的加剧，3种草地的根系周转速率呈逐渐降低的趋势，分别为1.70次/a、1.36次/a和0.87次/a。;Rocky desertification is a major kind of land desertification. The degradation land of karst rocky desertification is one of the most serious problems on economic development, ecosystem restoration and reconstruction in Southwest China. Grassland is one of the main vegetation types in karst region of Guizhou, its root is sensitive to the response of to environmental conditions, which determines the growth and development of plants and soil nutrition status. Root dynamics also has an indicator effect on environmental changes, and can reflect the health status of grassland ecosystem. As the intermediary connecting the aboveground and underground parts of vegetation, root plays an important role in the matter exchange and energy transfer between plants and soil, root decomposition and turnover contributes significantly to element cycling in grassland ecosystems. In order to identify the root dynamics and their response to rocky desertification in different grasslands in the karst region, this paper took three different rocky desertification grasslands (potential rocky desertification grasslands, moderate rocky desertification grasslands, and intensity rocky desertification grasslands) as research objects. The continuous soil drilling method and root bag method were used to investigate the monthly root dynamic, root production and turnover from March 2017 to January 2018. The results show that the root biomass of the three rocky desertification grasslands decreased gradually with the depth of soil, root biomass in the 0-10 cm soil layer accounted for more than 57% of the total biomass in the 0-30 cm soil layer. The root biomass of potential and medium rocky desertification grasslands showed significantly seasonal variation of single-peak, and the root biomass of the severely rocky desertification grassland was not significant. The root decomposition rate all showed the ″fast-slow-fast″ status, was significantly influenced by soil organic carbon, total potassium, total nitrogen, soil water content, soil electrical conductivity, soil temperature in the three rocky desertification grasslands. When the complete decomposition rate reached 95%, 1174, 1351 and 1878 days were needed in the three grasslands, respectively. With the intensifying of rocky desertification, the root turnover rate decreased gradually, and were 1.70 times/year, 1.36 times/year, and 0.87 times/year in the three grasslands, respectively. The above conclusions provide an important scientific basis for a deeper understanding of the nutrient cycle, soil fertility maintaining and the restoration of rocky desertification grasslands. It is necessary to strengthen the research on the nutrient release mechanism of the root in rocky desertification grassland in Southwest China.

哈尼梯田湿地生态系统健康评价指标体系构建

为了获得梯田湿地生态系统健康评价的指标体系，以云南红河哈尼梯田湿地为例，基于对该湿地维持机制的分析，构建了包括生态特征、功能整合、社会与政治3个方面共20个指标的健康评价指标体系以及各个指标的健康阈值分级表。同时，利用AHP层次分析法确定了各指标的权重，运用综合评价法对梯田湿地生态系统的健康状态进行评价。本研究构建的评价指标体系解决了哈尼梯田湿地生态系统缺乏健康评价指标体系和支持理论的问题，为评价该类型湿地生态系统的健康状态提供指导方法，能够依据其评价结果为后续湿地健康质量的提升及湿地的可持续利用发展提出改进策略。;Wetland plays an extremely important role in maintaining biodiversity, improving water quality, regulating microclimate, and protecting water and soil. With the unreasonable human activities, the ecological problems of wetland are becoming more and more serious, so the evaluation and diagnosis of wetland ecosystem health is extremely urgent. Hani terrace wetland is a special artificial paddy field wetland in southwest mountain area. It has not only important wetland ecological function value, but also agricultural production and national cultural value. At present, the research on Hani terrace wetland ecosystem mainly involves economic culture, ecological security and landscape tourism, while the research on ecosystem health evaluation is few. By analyzing the maintenance mechanism of the ecological balance of Hani terrace wetland and establishing a scientific health evaluation system to evaluate the health of the wetland, we can better understand the health status of the wetland, provide scientific support for the planning and utilization of the wetland and promote the sustainable development of the wetland. The unique vertical spatial structure of forest-village-terrace-river in the Hani terrace wetland is the maintenance mechanism of healthy balance of wetland ecosystem. Each part is independent and indivisible, with integrity. At this time, Hani terrace wetland ecosystem is not only the ecological subsystem of terrace wetland, but also the health evaluation of the whole forest-village-terrace river system. Based on the analysis of the maintenance mechanism, this paper constructed a health evaluation index system of 20 indicators including ecological characteristics, functional integration, social and political aspects and a health threshold grading table of each indicator. Meanwhile, AHP analytic hierarchy process is used to determine the weight of each index, and comprehensive evaluation method is used to evaluate the health status of Hani terrace wetland ecosystem later. The evaluation index system constructed in this study solves the problem of the lack of health evaluation index system and provides a guiding method for the evaluation of the health status of this type of wetland ecosystem. According to the evaluation results, improvement strategies can be proposed for the subsequent improvement of wetland health quality and sustainable utilization development of wetlands.

The Status of Canopy Density and above Ground Biomass along the Northern Coastal Forest Zone of Tanzania

Canopy density and forest biomass estimation are critical for understanding of the carbon cycle, climate change and detecting health status of the forest ecosystems. This study was conducted on the coastal forests reserves in Zanzibar and mainland Tanzania. A systematic sampling design was used to establish a total of 110 temporary sample plots in all study sites. The stratification of the forests was adopted to identify closed forest patches with less anthropogenic effects. The study assessed the forest canopy density and above ground biomass with relative carbon stock for closed forest classes. Jozani Chwaka Bay National Park in Zanzibar recorded higher average canopy densities of 63% followed by Ngezi (46%), Pugu forests (26%) and Kazimzumbwi (16%). However, Ngezi forest had higher forest biomass than all study sites with the overall mean AGB of 138.5 tAGB/ha equivalent to carbon stock of 67.9 tC/ha. Tree species, Bombax rhodognaphala (Msufi mwitu) and Antiaris toxicaria (Mgulele) recorded the highest biomass of 1099 tABG/ha and 703 tAGB/ha (equivalent to 538 tC/ha and (345 tC/ha)) respectively. The study revealed that about 35% of the total closed forest patches at Pugu FR were covered by lower canopy density which accounted about 490 ha. Kazimzumbwi FR was dominated by lower canopy density which represented about 64% of the total forest cover area (1750 ha).

基于遥感总初级生产力的天山-塔里木绿洲地区生态系统脆弱性研究

生态系统的脆弱性是全球气候变化与可持续发展研究的核心问题，测定与评价脆弱性对认识生态系统的结构与功能至关重要。天山-塔里木绿洲地区包含着山地、荒漠和绿洲等多种类型的生态系统，存在着多个不同生态类型的交界过渡区。为定量评价该地区生态脆弱性，以植被总初级生产力这一生态系统重要的功能性指标为基础，对该地区生态系统脆弱性进行了计算和分级（不脆弱、轻度脆弱、中度脆弱、重度脆弱和极度脆弱），并对研究区生态系统脆弱性的空间分布特征及其与环境因子的关系进行了分析与讨论。结果表明：（1）研究区生态系统脆弱性总体上表现出明显的空间分化格局，以中度和重度脆弱为主，极度脆弱的地区主要分布在南部的塔里木绿洲。（2）生态系统脆弱等级大体上随着区域内多年平均温度的升高而升高。受地表水灌溉的影响，生态系统脆弱性与降水量间并无明显趋势性规律。（3）研究区的生态系统脆弱等级随着区域内的平均海拔以及平均坡度的升高都呈现下降的趋势。受自然条件恶劣、过度放牧以及农田过度开垦的影响，目前该地区总体呈现脆弱性严重的状态。研究表明该地区应积极开展生态治理工作，合理规划生态功能关键区，保护好现有草原和湿地等易开垦地区，划定绿洲开发范围的"红线"，限制农田的开垦，协调好塔里木河流域的水资源分配。研究为使用卫星遥感数据研究生态系统脆弱性提供了方法上的参考，为可持续发展和生态治理提供了科学依据。;Ecosystem vulnerability is a core issue of global climate change and sustainable development research. Measuring and evaluating of vulnerability are essential for understanding the structure and function of ecosystems. Tianshan-Tarim Oasis contains multiple types of ecosystems such as mountain, desert and oasis, and there are many ecotones between different ecological types. Gross primary productivity (GPP) of vegetation, which is the total amount of carbon uptake by vegetation photosynthesis, is an important functional indicator of terrestrial ecosystem. GPP is not only an important index to measure the health status of ecosystem, but also a result of comprehensive effects of the environmental limiting factors on ecosystem. The fluctuation of vegetation productivity can also be used as an indicator to measure the vulnerability of ecosystem. In this study, GPP products with a spatial resolution of 1 km retrieved from Moderate-resolution Imaging Spectroradiometer (MODIS) were chosen to calculate and evaluate the ecosystem vulnerability of the study area. Based on vegetation productivity, the vulnerability of the study area is calculated and classified into not vulnerable, mild vulnerable, moderate vulnerable, severe vulnerable, and extreme vulnerable. The spatial distribution characteristics of ecosystem vulnerability and its relationship with environmental factors were also analyzed and discussed. The results showed that:(1) the ecosystem vulnerability of the study area presented an obvious spatial differentiation pattern on the whole, with moderate and severe vulnerability as the main feature, and the extremely vulnerable areas were mainly distributed in the southern Tarim Oasis; (2) the vulnerability of the ecosystem generally increased with the rise of the mean annual temperature in the region. Affected by surface water irrigation, there was no obvious trend between ecosystem vulnerability and precipitation; (3) the vulnerability of the ecosystem in the study area indicated a downward trend with the increase of the average altitude and the average slope in the area. Due to harshly natural conditions, overgrazing and over-exploitation of farmland, the area currently showed a state of serious vulnerability. Therefore, the ecological governance should be actively carried out, the key areas of ecological functions should be rationally planned, grassland, wetland and other easy-to-reclaim areas should be protected, the red line of the scope of oasis development should be delineated, farmland reclamation should be restricted, and the distribution of water resources in the Tarim River Basin should be coordinated. This study provides a methodological reference for using satellite remote sensing data to study the vulnerability of ecosystems, and provides a scientific evidence for sustainable development and ecological governance.

The Health Evaluation of Wetland Ecosystem in the Yangtze River Economic Zone Based on Remote Sensing——A Case Study of Yunnan Wetland

In order to provide a scientific basis for the development of the Yunnan wetland ecosystem, we construct a wetland ecosystem health evaluation system with 15 evaluation indexes selected from three aspects including pressure, status and response based on PSR mathematical model. Analytic Hierarchy Process(AHP) was used to determine the weight of indicators and the Yunnan wetland ecosystem was divided into “the five health status” of “health, sub-health, fragility, illness, and scurviness”, which are used to analyze and evaluate the health status of it through a comprehensive evaluation index. The results show that the comprehensive evaluation index of ecosystem health status of Yunnan wetland is 0.5524 in 2017, locating in the grade of “fragility” and is close to the status of “sub-healthy”; Among the 3 levels of pressure, state, and response, the pressure and state are locating in the grade of “fragility” and the response is close to the status of “health”. Among the 15 evaluation indexes, the rate of change of wetland area, the area of water body, the hydrological regulation and the wetland management level are the most important factors affecting the ecosystem health of Yunnan wetland.

A comprehensive evaluation method for plateau freshwater lakes: a case in the Erhai Lake

ABSTRACT The study first systematically assessed the ecosystem health status of the plateau freshwater lake of Erhai Lake in Yunnan Province of China, using the revised Freshwater Health Indicator methodology, which comprised three components, i.e., “Ecosystem Vitality,” “Ecosystem Services,” and “Governance and Stakeholders.” To better reflect the real health status of the basin, the cask short board effect was considered during aggregation of the indicators. In addition, analysis of the coupling coordination relationship among the three components was conducted to study the mutual influences among them as well as the comprehensive development level of the studied area. Basically, the ecosystem of the Erhai Lake basin remained healthy during the studied period according to the research due to specific measures and actions taken to manage the environmental problems caused by a former local economic development and urbanization process. However, there were still aspects to improve for more sustainable ecosystem management and utilization in the basin. The “short boards” of the Erhai Lake basin show room for improvement in local freshwater ecosystem management and underline governance problems that need to be addressed. Suggestions are provided for the local stakeholders consequently for the more sustainable development of the studied basin.

First report of Cystoseira aurantia Kützing from the Mediterranean coast of Morocco

Abstract Algal diversity in aquatic environments can help assess the health status of ecosystems, provide information about invasions of new species and inform species diversity changes according to environmental conditions. An algal diversity survey (2016–19) of Nador Lagoon (northern Morocco) revealed the presence for the first time of the brown alga Cystoseira aurantia. Since 2015 this alga has been found in high abundance in the northwestern part of the lagoon, mainly around Attalayoun and Nador City. The thalli of larger specimens reached 60 cm in length, and all plants present were free-floating. The species was collected from the water surface to depths not exceeding 2 cm. Floating patches were usually found suspended above sandy and muddy substrates. Increased abundance of this species in the lagoon corresponds with new physico-chemical conditions and ecological parameters, principally resulting from increased water ventilation and improved water quality since 2012. The new communities of C. aurantia may offer a novel resource for the lagoon but high abundance could pose future threats to attached vegetation such as seagrasses and benthic algae by shading and the accumulation of organic detritus. Attention is drawn to taxonomic issues involving C. aurantia.

Wastewater remediation of heavy metals and pesticides using rice straw and/or zeolite as bioadsorbents and assessment of treated wastewater reuse in the culture of Nile tilapia (Oreochromis niloticus).

The remediation of wastewater (WW) is a promising solution for limited water sources. This study aimed to evaluate rice straw (RS) and zeolite (Z) as bioadsorbents for the removal of pollutants, including heavy metals (HMs) (cadmium [Cd], nickel [Ni], and lead [Pb]) and malathion (PC), from WW and to assess the suitability of reusing remediated WW in fish rearing units. A total of 11 treatment groups with 3 replicates each were designed with different combinations of RS and/or Z for the treatment of real WW contaminated with HMs and malathion, where the WW remained in contact with the adsorbents for 24h. Different remediated WWs were used for rearing Nile tilapia (Oreochromis niloticus), which were randomly allocated into 33 glass aquaria representing 11 treatments with 3 replicates each for 30days. The best remediation efficiency was achieved using a mixture of whole RS (WRS), chopped RS (CRS), and Z (HM-PC-WRS-CRS-Z group), with removal percentages of 92%, 95%, 96%, and 99% for Cd, Ni, Pb, and malathion, respectively. The health status of the aquatic ecosystems was assessed through blood tests to characterize biochemical parameters and through pathological changes of cultured O. niloticus reared in treated WW. A significant (P˂0.05) effect on the blood biochemistry of fish reared in treated WW was found and better biochemical and histologic architecture was observed than that of fish reared in untreated WW. A novel mixture of WRS, CRS, and Z could possibly be a promising low-cost adsorbent for wastewater treatment. Graphical abstract.

Community characteristics of benthic macroinvertebrates and identification of environmental driving factors in rivers in semi-arid areas – A case study of Wei River Basin, China

The characteristics of the benthic community structure can effectively reflect the health status of the river ecosystem and the quality of the river ecological environment. It is of great significance to identify the limiting factors of benthic community structure for the maintenance of river ecosystem health. As a typical semi-arid ecological fragile area, the eco-environmental problems in the Wei River basin have become increasingly prominent. The benthic community structure is affected by multiple stresses such as habitat degradation and water quality deterioration. In this study, 18 national monitoring stations were selected to investigate the ecological environment and benthic invertebrate community characteristics in the Wei River basin in October 2019. W-statistics, Shannon-Winer index, Pielou index, Margalef index, and B-IBI index were selected to evaluate the community characteristics of benthic macroinvertebrates from three aspects of the community stability, community diversity, and community integrity. Principal component analysis, Pearson correlation analysis, and canonical correspondence analysis were used to analyze the correlation and variability between zoobenthos community index and environmental factors. The results showed that the spatial difference of benthic community structure in the Wei River basin was not significant, and the Sal, NH3-N, Tub, DO in water environment and heavy metals in sediment were the main environmental factors affecting the community structure of benthos. Improving water quality and controlling pollution were the main strategies to improve benthic biodiversity and promote sustainable development in the Wei River basin.

A integrated method for assessing the urban ecosystem health of rapid urbanized area in China based on SFPHD framework

With the rapid economic development and continuous growth of population in rapid urbanized area, the health status of urban ecosystem is undergoing profound changes, which will have a negative impact on the sustainable development. In order to systematically evaluate the health status of urban ecosystem in rapid urbanized area of central China, this paper puts forward a new assessment framework of structure-function-process-human health-development based on a deep understanding of the concept and general characteristics of urban ecosystem health, and establishes an expanded evaluation index system according to this evaluation framework. Then, on the basis of determining the index classification criteria in detail, the improved SI-MI model was used to evaluate the health status of urban ecosystem. As a case study, the framework and method were applied to the urban agglomeration in the middle reaches of the Yangtze river, a region of the rapid urbanized in China. The results showed that, the health level of most cities in the study area has been improved from 2005 to 2015. From the perspective of spatial pattern, the health level of the study area shows obvious spatial heterogeneity, and provincial capital cities and some eco-cities have better health status. It is worth noting that the function and development layer are the key parts that restrict the overall health level of urban ecosystem in the urban agglomeration in the middle reaches of the Yangtze River. After classifying all cities, we found the factors influencing the health level of different types of cities, and proposed the management suggestions for different types of cities.

The panpulmonate limpet Siphonaria lessonii Blainville, 1827 as a sentinel of contamination in coastal areas of Argentina

Although some studies have evaluated the use of Siphonaria lessonii as a bioindicator of pollution, no study has identified the effects of human activities on the digestive gland, which is the main centre of detoxification of xenobiotics and a target organ in contamination studies. Thus, the present work aims to evaluate the use of this species as a suitable sentinel of contamination by analysing the digestive gland and shell alterations. The study was carried out in three populations exposed to different degrees of anthropogenic impact in the coast of Buenos Aires: a reference site (VG), a mid-impacted site (MPL) and a highly-impacted site (MPP). A histological analysis of the digestive gland was performed, as well as an assessment of the geometric morphometry, thickness, density and microstructure of the shell. Our results indicated that the individuals from the impacted sites present several histological alterations in the tubules of the digestive gland. These included hypertrophy and hyperplasia of different cell types (MPP), alterations of the digestive tube morphology (MPL and MPP), the presence of lipofuscin-like substances (MPL) and a high inflammatory response (MPP). In the shells, neither microstructural malformations nor changes in the elemental composition were found. However, shell morphometric variations and a decrease in shell hardness (thickness and density) were observed in the impacted sites. In conclusion, our results indicate that S.lessonii is a well-suited sentinel of contamination since the effects of anthropogenic impact may be reflected in both soft and hard structures. Although further investigations are necessary to identify the relationship between these effects and their potential causing agents, these simple and low-cost methodological approaches could be used to diagnose disturbance in the ecosystem health status where this species inhabits.

Bioindication of the ecological state (health) of coastal waters based on the use of automatic bioelectronic systems

The paper presents the data obtained in the study of the health of the ecosystems in a number of recreational areas of the Black Sea and the Eastern Gulf of Finland. Prompt assessment of the health of the ecosystems was carried out by testing the health of adult bivalve mollusks inhabiting them, using the functional load method based on the analysis of their heart rate measured by a fiber-optic bioelectronic system. The goal of the study is to test the innovative bioindication technology developed earlier by the authors on the basis of the above-mentioned method in the regional programs for environmental monitoring of the ecosystems of coastal marine and freshwater recreational water areas (using the example of a number of water areas of Sevastopol, as well as several freshwater areas of the Kurortniy District of St. Petersburg. It has been established that the functional state of mollusks may serve as an indicator of excessive pollution of coastal waters by the objects that discharge insufficiently treated wastewater from their local treatment facilities, including household wastewater. The technology applied in this study for the assessment of functional state of local species of molluscs may be effectively used to solve the problems of early diagnostics of alterations in the health status of coastal aquatic ecosystems and contribute to ensuring the ecological safety of recreational water areas, serving as an infobase for the development of science-based environmental management decisions. Taking into account a high expressiveness and easy-to-use technology applied in the study (which does not require expertise for its practical implementation), this technology may be considered as the best available technology for biomonitoring the water quality of recreational waters in Russia.

Research note: Ecosystem Health (EH) assessment of a rapidly urbanizing metropolitan city region of eastern India – A study on Kolkata Metropolitan Area

Assessment of ecosystem health (EH) in Indian megacities is urgently required where ineffective environmental protection policies turned them into hotspots of a bundle of eco-environmental problems. In this study, the classic Vigor-Organization-Resilience (VOR) framework was employed to devise the ecosystem health index (EHI) of Kolkata megacity which is similar to the work of Peng et. al. (2015). Results show that EH of this megacity city region was rapidly deteriorating trend, from 0.627 to 0.377 with strong spatial heterogeneity. In 2000, areal coverage of EH status of relatively well was 73.10% reduced to 52.00% and areal coverage of weak EH status increased to 21.80% in 2019. The relatively weak and weak status of EH are concentrated in Kolkata, Howrah and its adjacent areas. The study proposed a new improvement and deterioration index to track the changes of EH at the city scale to overcome the limitation of the percentage change method. Ultimately the outcome of the study provides a better understanding of EH in Kolkata megacity region that is helpful for policymakers in developing measures for eco-environmental management.

Use of ecosystem health indicators for assessing anthropogenic impacts on freshwaters in Argentina: a review.

Indicators of ecosystem health are effective tools to assess freshwater ecosystem impairment. However, they are scarcely used as a monitoring tool by local environmental agencies in Argentina. Here, we review the literature to analyze the use of ecosystem health indicators in freshwaters from Argentina. We found 91 scientific articles relating to the use of ecological indices to assess the impact of different environmental stressors in aquatic environments published between 1996 and 2019. We generated Google Earth map where we deployed the sampling sites and type of indices reported by each article. As biological indices were the most used, we also surveyed bioindication experts to gather information on their application. We found that most studies were concentrated mainly in Pampas (34%), Dry Chaco (20%), Espinal (12%), and Patagonian Steppe (10%) ecoregions. Biological indices (mainly with invertebrates) were more used than geomorphological or physico-chemical indices. Indices resulted useful to evaluate the impact of stressors in 63% of cases, being land use the most studied stressor. However, sampling design varied greatly among studies, making their comparison difficult. The information compiled here could help to the design of monitoring protocols, the adoption of regional indices, and the creation of a national inventory of ecosystem health status, which are mandatory to propose well-grounded conservation and management policies for freshwaters in Argentina.

Study on Global Burned Forest Areas Based on Landsat Data

Forests are an extremely valuable natural resource for human development. Satellite remote sensing technology has been widely used in global and regional forest monitoring and management. Accurate data on forest degradation and disturbances due to forest fire is important to understand forest ecosystem health and forest cover conditions. For a long time, satellite-based global burned area products were only available at coarse native spatial resolution, which was difficult for detecting small and highly fragmented fires. In order to analyze global burned forest areas at finer spatial resolution, in this study a novel, multi-year 30 meter resolution global burned forest area product was generated and released based on Landsat time series data. Statistics indicate that in 2000, 2005, 2010, 2015, and 2018 the total area of burned forest land in the world was 94.14 million hm2, 96.65 million hm2, 59.52 million hm2, 76.42 million hm2, and 83.70 million hm2, respectively, with an average value of 82.09 million hm2. Spatial distribution patterns of global burned forest areas were investigated across different continents and climatic domains. It was found that burned forest areas were mainly distributed in Africa and Oceania, which accounted for approximately 73.85% and 6.81% of the globe, respectively. By climatic domain, the largest burned forest areas occurred in the tropics, with proportions between 88.44% and 95.05% of the world's total during the study period. Multi-year dynamic analysis shows the global burned forest areas varied considerably due to global climate anomalies, e.g., the La Niña phenomenon.